I guess Cicero had suffered more from the consequences of his actions than the others up to that point (he'd ended up exiled and having his houses burnt, etc. because of the Catilinarians), so he was more cautious.

But he hated Antony and wanted him dead which did motivate him at the end. What I think they've got right is that Cicero isn't an aristocrat through and through and that is affecting the relationship with Brutus, but I seriously think that for all of his awful faults and weaknesses that he was the last man who actually believed in the Republic as an idea, rather than being an opportunist.

You are probably right about Pullo, but Octavian is such a cold bastard that I wonder if they'll have him perform some drastic betrayal at the end to solidify him as Augustus.

And I like your speculation about Octavia...